Wednesday was the final day for victims of the Khmer Rouge to apply for civil party status in the court's much-criticized third case. But tribunal observers and victims' rights activists fear Case Three is on the verge of being shut down.

Less than three weeks ago the investigating judges at the war crimes tribunal here announced they had closed their file in the court's third case against former senior leaders of the Khmer Rouge.

Cambodian news media have identified the suspects in the case as two former high-ranking Khmer Rouge military officers.

The tribunal is investigating crimes against humanity and genocide in the around two million Cambodian deaths from starvation, overwork and executions during the Khmer Rouge's reign between 1975 and 1979.

The tribunal's third case is highly controversial, mainly because the Cambodian government has long said it will permit only the first two cases to proceed to trial.

That raised a storm of criticism over allegations the government was meddling in what is meant to be an independent judicial process.

The controversy has not stopped there.

Recent comments by the international prosecutor Andrew Cayley indicate that the investigating judges' work in Case Three was deficient.

Last week Cayley said Case Three needed much more work.

"If you're asking me how much more investigation needs to be done, I would simply use the words "a significant amount" of investigation is still left to be done in that case," he said.

The controversy in Case Three goes further still.

The Khmer Rouge tribunal was the first of its kind to allow victims of specific crimes - known as civil parties - to participate.

Nearly 100 people took part in Case One, and around 4,000 have registered for Case Two, in which the Khmer Rouge's four senior surviving leaders will be tried for genocide and other crimes.

But the investigating judges did not release any information about Case Three, which meant people could not know whether the crimes under investigation affected them.

Just over a week ago the international prosecutor Andrew Cayley published that information, a move that prompted the international investigating judge Siegfried Blunk to order Cayley to retract his statement, which also pointed out deficiencies in the investigating judges' casework.

Blunk on Wednesday gave Cayley three days to comply, but has not specified what will happen if he fails to do meet that deadline.

Clair Duffy is a tribunal monitor with the Open Society Justice Initiative, an organization funded by U.S. billionaire George Soros.

She says Cayley was merely doing his job.

"The international co-prosecutor's acted independently and carried out his legal duty in identifying major gaps in the Case Three investigation, and in seeking further investigative acts," she said.

She says this episode could damage the tribunal.

"The potential message of this kind of action is that those seeking to act independently of political will, and to act with integrity in the pursuit of justice will be laying themselves open to criminal sanction," she said.

Wednesday marked the final day for civil party applications in Case Three.

But the investigating judges' silence has meant very few people even know about the case. Around 300 managed to apply by the 4 p.m. deadline.

Blunk's office has already rejected at least two, one of whom is New Zealand Olympic rower Rob Hamill.

His brother Kerry Hamill was abducted by the Khmer Rouge from his yacht off the Cambodian coast in 1978, taken to S-21 prison in Phnom Penh, and tortured before being executed.

Rob Hamill was a civil party in Case One, in which the former commandant of S-21 was convicted of war crimes and crimes against humanity. He was also accepted as a civil party in Case Two.

But the investigating judges turned him down for Case Three, a decision Hamill says is "incomprehensible and schizophrenic" given that one of those thought to be involved in Case Three was the head of the Khmer Rouge's navy.